How to configure key mapping with the VNC plugin.
Remmina has an hidden feature with which you can configure custom key mappings, this is useful if you need, for example, to map the local Super key to the remote macOS Option key (leaving theexisting local Alt key to the remote macOS Command key map alone.)
See #1716 for a long discussion about this.
Keys can be mapped according to a configurable map. There is a predefined map called "Map Meta Key" that seems to be exactly what we need for macOS.
Edit your connection profile, under "Basic settings", you will find "Keyboard mapping". Choose "Map Meta Keys".
Save and connect.
Map Meta Keys is the following map:
[Map Meta Keys] Super_L = Meta_L Super_R = Meta_R Meta_L = Super_L Meta_R = Super_R
Other maps, using the same syntax, can be created in the
remmina.keymap file, located in the same directory as the remmina.pref file, usually
~/.config/remmina/remmina.keymap Key symbol names can be found on the GDK file gdk/gdkkeysyms.h.